Electric water heater



May 29, 1928.

1,671,677 H. H. KEETON ELECTRIC WATER HEATER Filed March 14, 1927Patented lVlay 29, 1923.

UNITED STATES ream PATIENT orrics.

HENRY H. KEETON, OF RICHMOND, VIRGINIA.

ELECTRIC WATER HEATER.

Application filed March 14, 1927. Serial No. 175,219.

. ever is described by or is included within the terms or scope of theappended claims.

In'the drawings: r 'Fig. 1 is a View of the complete heater. Figure 2 isa vertical section through a heater embodying my invention.

Briefly described, my heater comprises an external shell of hollowcylindrical or tubular form with threaded holes at top and bottom forthe pipe copnections with the boiler, an internal shell spaced from theinterior of the outer shell to provide the water space, in which spaceis a spiral reaching from top to bottom which forms a tortuous or spiralpassage for the water through the heater, an electrical heating unitwithin the inner shell, and a detachableclosure at the bottom of theouter shell which has an electrical socket to which the heater unit is.

detachably connected.

Describing in detailwhat is shown in the drawings, the outer shell, 10,preferably of brass, is cast in one piece, its top being domeshape, andprovided with a central threaded hole, 11, for the pipe connection, andits :5 bottom being open and provided with internal screw thread for thedetachable connection of the plug 12, and having just above the lowerend an inwardly projecting annular flange, 13, which forms the bottom ofthe water space in which just above the flange opens a screw threadedopening, 14, for the attachment of the other pipe connection with theboiler, and to which flange is attached,

as by electric welding, the inner shell, 15,

preferably of copper, which is closed at the top, but open at thebottom, being in effect a tube closed at the'upper end. The shell, 15,at the bottom has an outwardly turned flange,16, which overlaps themargin of the flan e, 13, and forms a art of the connection etween thetwo. e space within the inner shell, 15, is to accommodate the heaterunit, 17, which is of the type comprising a porcelain'core or bar, withthe re- 7 5 sistance coil, 18, wound spirally about it from top tobottom, this being of standard construction, and because the coil is onthe exterior of the-core, it is important to prevent its contact withthe copper inner shell, 15, to avoid short circuiting, and -to that endat top and bottom the porcelain bar has an annular enlargement orprojection, 19, which contacts with the copper shell on the interior,and thus maintains a space between the shell and the resistance coil.The heater unit has. at its lower end a plug, 20, which screws into asocket, '21, of standard twopart construction, which screw together andclamp the'margins of a central hole, 22, in the bottom of the plug, 12.It will be seen that when a heater unit burns out or is otherwise unfitfor use,, it is a very simple matter merely by unscrewing the plug, 12,to withdraw the unit along with the plug and then the unit may beunscrewed from the socket and a fresh unit substituted.

Within the internal space between the inner and outer shell is a spiral,23, of metal that winds from top to bottom of the space, and is of thinribbon-like material, so that while serving the purpose of delaying thepassage of water through the heater, it'occupies a minimum of space, andsuch spiral is cast to the inner wall of the outer shell, 10.

It will be seen that disregarding the heater unit and the socket member,my device consists of but four parts, namely, the external shell, 10,the plug, 12, the inner shell, 15, and the spiral, 23. The exterior issmooth and free from external abrupt projections, so that it is not onlylight and attractive looking, but it is free from any external abruptsurface upon which dust or dirt can lodge that would be both unsightlyand difiicult to remove.

What I claim is:

1. An electrical water heater comprising an external shell with integralside and top walls, a removable plug closing the bottom, said shellhaving above the plug an integral I00 inwardly projecting flange, aninner shell closed at the top and open at the bottom and joined to saidflange at the bottom, and an electrical heater unit supported within theinner shell from said plug and removable 106 and replaceable with theplug, said plug having an electrical socket connection with which saidunit is detachably connected.

2. An electrical water heater comprising an external shell with integralside and top 1].

2 i 1,e71,m

walls. a removable plug closing the bottom, placeable with the plug, anda ribbon-like said shell having above the plug an integral sgiralattached to the interior of the outer inwardly projecting flange, aninner shell s oil and reachin therefrom to the exterior 10' closed atthe top and open at the bottom and of the inner shel v I! joined to saidflange at the bottom, an elec-- In testimony whereof I hereunto afiix mytrical heater unit supported within the inner signature. shell from saidplug and removable and ro- HENRY H. KEETON.

